Pre-heat your oven to 220ºC/200ºC fan.

Use a sharp knife to cut slits in your potatoes. These should be about half a centimeter apart and go about two-thirds of the way through the potato - it's important that the slits do not go all the way through otherwise the potato will fall apart (although don't panic if you do accidentally cut all the way through, the recipe will still work). Try putting a wooden spoon either side of the potato while you're cutting and this should help stop you going all the way through.

Add 5g (about a teaspoon) of butter to the top of each potato and drizzle each one with a teaspoon of olive oil, then season with a pinch of salt.

Place them into the oven for 30 minutes. Dip a pastry brush into the melted butter and oil in the tray and brush it over the potatoes. Return to the oven for 20 minutes and then brush them in the oil and butter again. Cover the potatoes loosely with a sheet of foil (this stops them burning while they finish cooking) and return them to the over for a further 15 minutes.

While the potatoes are cooking, thinly slice the cheese (100g). Once the potatoes have cooked, remove the foil and stuff the sliced cheese into the slits in the potatoes. I tend to add the cheese into every other gap. You may need to use a knife to open the gaps a little to allow you to get the cheese in.

Return them to the oven for a further 5 minutes to allow the cheese to melt and then serve.